Heat insulation of buildings becomes more and more important. One method of heat insulating buildings, in particular existing buildings, is to improve the heat insulation of large building surfaces such as walls and ceilings. It is well-known to coat interior surfaces of buildings with a composition with heat insulation properties to improve the heat insulation capacity of such building surfaces.
Such coating compositions typically comprise hollow microspheres, usually hollow glass microspheres. In US2015/0176267 is for example disclosed a coating composition with a low thermal conductivity that comprises 4 to 17 wt % of hollow microspheres, 5 to 25 wt % of a water-dispersible or water-soluble binder polymer, 25 to 50 wt % of a mineral or metallic filler, 0.05 to 1 wt % of a linear fatty alcohol and 0.1 to 1 wt % of a thickener, and water. The coating composition is used as smoothening and/or heat-insulating coating for walls and ceilings.
The coating composition of US2015/0176267 comprises a significant amount of non-hollow mineral filler. Fatty alcohol is needed to avoid cracking of the coating.
There is a need in the art for coating compositions for building surfaces with improved heat insulation properties, which are easy to handle and can be applied as a single layer of sufficient and even thickness that does not crack and provides the desired degree of thermal insulation.